Variable stiffness coil for vasoocclusive devices

Abstract

The variable stiffness vasoocclusive coil is given variable stiffness along the length of the coil by selectively heat treating certain segments of a primary or secondary coil. The primary coil can be selectively heat treated to form soft or deformable segments along the length of the coil, and can then be shaped into a secondary shape that is set by a heat treatment process. Distal regions of the coil can also be heat treated to make the distal ends of the coil softer, more deformable, or less traumatic.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates generally to implantable devices for interventional therapeutic treatment or vascular surgery, and more particularly concerns a variable stiffness vasoocclusive coil that exhibits variable stiffness along the length of the coil.2. Description of Related ArtThe art and science of interventional therapy and surgery has continually progressed towards treatment of internal defects and diseases by use of ever smaller incisions or access through the vasculature or body openings in order to reduce the trauma to tissue surrounding the treatment site. One important aspect of such treatments involves the use of catheters to place therapeutic devices at a treatment site by access through the vasculature. Examples of such procedures include transluminal angioplasty, placement of stents to reinforce the walls of a blood vessel or the like and the use of vasoocclusive devices to treat defects in the vasculature. There is a...

AI Technical Summary

Benefits of technology

"The present invention provides a variable stiffness vasoocclusive coil that can be used for interventional therapy and vascular surgery. The coil is made of a shape memory metal that can be heat treated to change its stiffness. The coil has a primary coil configuration and can be shaped into a secondary shape to conform to the shape of the vessel or malformation. The coil can be made more flexible or less traumatic by heating certain segments of the coil. The invention allows for the coil to deform in a random three-dimensional shape to conform to the shape of the vessel or malformation. The invention provides an occlusive device that can be easily inserted into a portion of a vasculature for occluding the portion of the vasculature of a patient. The invention also provides a method for making the variable stiffness coil by heat treating segments of the coil to cause them to have reduced stiffness."

Problems solved by technology

However, substantial risks to a patient are involved in such a procedure, and a coil which has soft or deformable segments may offer less risk to a patient.

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